probe_error() frees memory only, if cgdev->dev.driver_data refers
to the claw_privbk structure. Move forward its setting in claw_probe()
to ensure proper freeing of claw_privbk allocations.

Cc: Daniel <danielm77@spray.se>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>